Illustrators and designers seem to love the devices. Big surfaces with a precise pencil signal the end of the expensive Cintiq devices.

Writers (bloggers, journalists) complain that they miss the mouse/track pad on these devices. It is hard to go back and forth from keyboard to screen to move quickly through text and cut/paste sentences.

Presentation design might actually be a good fit for a bigger tablet, if you can make things run smoothly without the need for the attached physical keyboard. It would require a redesign of the user interface though, the mouse-based UI is too complicated, and the current mobile UIs are too counter-intuitive, many functions are hidden. SlideMagic might fit the bill, I am going to find out soon.

Still, there is the difference between "it works great" and mass adoption in big enterprises...